


Old Data, New Experiment

by dandelionknight



Series: Bubbline week 2019 [2]
Category: Adventure Time
Genre: Campfires, F/F, Hanging Out, Secrets
Language: English
Status: Completed
Published: 2019-03-19
Updated: 2019-03-19
Packaged: 2019-11-24 10:00:40
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,942
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18163736
Author URL: https://archiveofourown.org/users/dandelionknight/pseuds/dandelionknight
Summary: Bonnibel has been acting strangely - more so than usual. Marceline is curious as to why.





	Old Data, New Experiment

Just as she expected, Marceline found the princess in her lab hunched over some new formula she was working on. No bubbling chemicals or humming electrical equipment this time; it was silent save for the periodic scratch of pen against paper and the occasional mutter.

She drifted to the other woman’s side and leaned over her shoulder.

“Whatcha working on?” 

The question was innocent enough but judging by Bonnibel’s reaction one would think she’d been accused of murder.

The princess yelped, jumping to her feet and twisting away, chair careening and clattering to the floor. The notebook was shut so fast the spine cracked in protest. It was the first time the vampire had seen it; thick but plain with a dark blue cover. 

“Marceline!” she squeaked. “I didn’t notice you come in!” Finally processing the question, she answered, “J-just a little science that all!” She forced a laugh, her smile a touch too wide. “You know how much I _love_ science!” 

“Uh, yep, you sure do.” Marceline rubbed the back of her neck. “I was just wondering if you were busy tonight.”

Bonnibel leaned against the table, book trapped safely under her arm as she looked up her friend, smile now genuine. “No, nothing that can’t wait. What’s up?”

“Campfire night with Finn and Jake. They said they’ve been trying to let you know but you haven’t replied so I decided I’d see what’s got our favourite brainlord so distracted on a Tuesday night. Also they want you to bring marshmallows.”

Once Bonnibel looked, her phone showed the notifications from a handful of texts and a few missed calls. Starlight and a midnight sky greeted her through the open window.

“Oh woops, guess I lost track of time. Just give me a bit and I’ll join you.”

“Must be _some_ experiment.”

The princess flushed, expression unreadable. “You could say that.”

The reaction struck her as odd but Marceline shrugged it off. 

“I’ll meet you by the gates. Lemme know when you’re ready.” 

\----

“Thanks boys,” Bonnibel waved with one hand while stuffing a large Tupperware container into her bag. 

“Don’t mention it Princess,” came the high pitch reply of some candy citizen Marceline couldn’t be bothered to recognize; there were far too many of them to keep track of the minor ones. 

Bonnibel had traded her lab coat for a bright, angular patterned windbreaker; a wise choice considering the autumnal chill in the air. If there was one thing the vampire didn’t miss about being mortal, it was being victim to the whims of temperature. 

“Kay, I got the ‘mallows,” the princess said, patting the satchel slung over her shoulder. “Let’s roll.” 

“How do you wanna do this? Princess or analog jetpack style?” Marceline asked.

“Jetpack.”

Marceline pulled the other woman into an embrace from behind, securely wrapping her thin arms around the younger woman’s torso before taking off. 

\-----

They had made quite the cozy set up for themselves. An old tree stump and two fallen logs served as seating around a fire that crackled cheerfully, casting its warm glow around the small clearing. Finn sat on the ground,  
leaning on one of the logs, his legs stretched out so that his feet nearly touched the fire. His half-eaten hotdog rested on his belly along with a few dark ketchup stains while he watched Jake’s rather unorthodox three-armed attempt at charades. 

“A volcano exploding,” BMO offered. Ketchup and mustard smeared on his screen and buttons, BMO returned to contentedly mashing his own food into his face.

“Wizard shooting fire at… a two headed giant!” Finn guessed. 

“Wrong again! It’s a warlock – oh hey you two,” Jake waved his extra limbs at the two women. 

“We kept your bass warm for you,” Finn said, gesturing the red axe bass propped beside him, a blanket around the neck of it with the remains of a hotdog on a paper plate set nearby. 

Marceline barely set the princess safely on the ground before she broke her hold to rush to the instrument’s side. 

“Dude! Don’t touch my stuff!” 

Instinct shifted her face into something monstrous as she snatched it back. By the time her forked tongue and gapping toothy maw returned to normal, Jake was quivering behind the stump that had served as his seat, the  
hotdog he was cooking abandoned to the flames. 

The teenager laughed, “Yeah, ok Marcy.” 

“Whatever.” She plucked a few chords experimentally. She knew the brothers wouldn’t wreck her bass on purpose but accidents followed the two of them like thunder after lightning; it was only nature. 

“Still in one piece?” Bonnibel asked with a hint of amusement in her voice. 

Marceline nodded and pulled Finn’s signature hat over his eyes with a snicker at his indignant ‘hey’. The friends relaxed and settled themselves into their chosen spots: Marceline floated beside Finn, Jake by himself and Bonnibel beside BMO. 

Jake stared forlorn at the charred remains of his food. His brother gestured for him to hand it over and the boy ate it with relish (but without the condiment). 

“Sorry about your dog, dawg,” Marceline said. 

“Its fine,” Jake speared two more for himself. “You want one Princess? 

“Sure.”

The princess stuck a forked branch into the ground and angled her stick for hands-free roasting. It wasn’t long before Marceline noticed the blue book from earlier at her side and covered by a discrete hand. 

It sparked her curiosity. Was there some kind of science geek conference coming up? The vampire couldn’t remember her mentioning anything but there was no use in thinking about it hungry. She snagged the ketchup bottle from Finn and drained the plastic container and its label of pigment.

“You bring the marshmallows PB?” Finn asked through the last of his food. 

She nodded and passed them to Jake’s outstretched hand so she didn’t have to get up. 

“These are kind of a weird shape. Did you make them yourself?”

“Something like that.”

For a while they just listened to the crackling of the fire, cooking up campfire fare to varying ideas of success. Everything Finn touched burnt but the teen said he preferred it that way. Bonnibel lit her second marshmallow on  
fire after she got distracted scribbling something down. Even Marceline toasted one, giving it to BMO to ‘eat’. 

“Who wants to hear a ghost story?” the little robot asked. The goopy sugar was stuck to his screen just under his mouth. 

Murmurs of agreement rose from around the now well-fed group.

“There was once a very lonely farmer; the loneliest farmer in the world. His wife had left him alone long ago and his sons too, to make money in the city. He lived so far away from everyone he didn’t have any friends.”

“Sounds like the Ice King,” Jake whispered not terribly subtly to Finn. They both giggled. Marceline made no comment but the pang in her chest. 

BMO continued, effecting a deeper voice for the farmer, “’Oh, if I don’t make some friends soon I’ll die’ the farmer cried as he worked in his field. But his tears were seen by nobody but crows and they fell into the soil one by  
one. When it was nighttime, the farmer went to sleep in his big, empty bed. The next day he did the same thing. He worked hard to grow his corn and cabbages and pumpkins for other people to eat and again he cried into the dirt. Nobody heard him but the wind. On the third day, the farmer still got up and watered his garden with sadness. Nobody hugged him but the vines. At night he listened to the silence of his home until he heard something knock on his door. He was scared because no one ever came to see him, but he still went to see who it was. When he opened the door, there was nothing. ‘Who’s there,’ he asked but nobody answered. The farmer walked into his field and looked around. ‘At least my vegetables don’t leave me,’ he said. When he went to go home, he never got closer. His legs felt like tree trunks and his feet got stuck in the dirt. He would never be lonely again.” 

All three stared at BMO and then at each other. 

“Okay,” Marceline mouthed.

“One day his family came to visit him but they couldn’t find him anywhere. He wasn’t in his bed or in the kitchen or in the bathroom. They wandered around the farm until they saw a weird scarecrow that looked like the  
farmer but…”

He slipped off his perch and grabbed a penlight from Finn’s backpack. He shone in on the flat plane of his chassis. “His head was a pumpkin!” 

“What did I tell you about listening to late night radio young man?” Jake said sternly. 

“No, it’s true! It’s about Mr. Williams. He is a very sad person.” The robot suppressed a shudder. “Do not dig in his fields even for fun.”

“Good one BMO, very spooky,” Bonnibel said.

“Alright, if you want something spooky I’ve got something that with scare the pants off of you guys,” Jake boasted. “It happened to me last month, when I was wandering the empty aisles of the Grocery Kingdom…”

“You went grocery shopping.” Marceline deadpanned.

“Well, yeah, but that’s not the whole story.”

He twisted his face into something a little beyond canine. The firelight cast strange shadows over his features.

“So there I was in aisle five, trying to find the Wheatloops when I heard it; a strange, florescent buzz as the lights above me flickered. I didn’t think much of it; I was too focused on the fact that a jug of milk is _four bucks_ now …”

Her eye caught a glimpse of pink in motion but when she turned, Bonnibel’s attention was firmly fixed on Jake and his story.

Marceline’s own attention drifted and she watched the other’s reactions instead. The slow dawn of horror on Finn’s face was hilarious, especially the progressive slackening of his jaw until his mouth hung wide open. She  
plucked a blade of grass and traced it on a little patch of exposed neck. The boy shrieked and shot up into the air, much to her delight. 

She felt, rather than saw, Bonnibel’s eyes on her again. They bored into her, burning like the sun. Watching out the corner of her eye, she meant to catch the other woman but every time she thought she would, her gaze was studiously elsewhere or focused on that notebook of hers. 

“And that’s why you should never go into the backroom even if they offer you the employee’s discount.”

“I will never enjoy cereal again,” BMO whispered, aghast.

“Me neither,” Finn agreed.

“Aww no dude please! We have _so many_ Wheatloops!”

 

“Hey Peebs I’ve been meaning to ask: what’s up with the book?” Finn voiced what had been sitting in Marceline’s mind.

“I just really need to get this…science done while I have inspiration in front of me.” Her eyes settled on Marceline for a moment before she quickly looked away. Was she pinker than usually or was it a trick or the light? ”I mean, uh, look at this fire! The chemistry of combustion is a wonderful thing, am I right?” Yet another awkward laugh. 

“You said it sista,” Jake said. He pulled a log from a little pile and tossed it into the fire. The flames devoured it hungrily, popping and sending up a plume of sparks. “But there’s a time for work and there’s a time for...” He paused for dramatic effect, “Truth or dare!”

“Ooooh,” BMO said appreciatively.

Bonnibel and Marceline exchanged a look. Too much truth was something neither woman was quite ready for; especially with an audience. 

“Alright then BMO,” Jake rubbed his hands together and grinned. “Make your choice. Truth! Or dare?”

“Dare!” 

“Hmm, I dare you to… let me draw something on your face!”

He nodded seriously, “I accept the charges.” He trotted over to Jake. “Do it.”

With a few squeaks of dry erase marker, BMO was sporting a new squiggly beard, moustache and thick lines for eyebrows. 

Jake chuckled to himself while admiring his handiwork.

“How do I look?” the robot asked. “Is my beautiful face ok?”

“You look very…uh, distinguished,” Marceline offered.

“You look like a bad guy,” said Finn. 

“It seems I must turn to a life of crime,” BMO said gravely. “Remember me with these last words Finn: truth or dare?”

“Uhhh…dare.”

“I dare you to drink the ketchup!” 

“Pssshht. He does that like all the time,” Jake teased. 

“No I don’t!” 

“Just do it!”

“Fine.”

Finn closed his eyes and opened his mouth. Thinking he positioned the bottle over his mouth, he received an initial splattering of ketchup to his cheek before he readjusted. 

“Gross,” the teen remarked, “definitely needs more hotdog.”

The four of them laughed at the boy until the princess gave in and offered him a handkerchief. 

“Marceline,” he said, turning to face her while cleaning his face. “Truth or dare?”

“Dare.”

“I dare you to not fly for the entire day.”

“Seriously?”

Finn nodded. ”I’m seriously serious.” 

“Ugh, fine.”

She let gravity take her and thumped to her seat, legs crossed and arms folded. 

“I dare Jake to give me a ride home after this.”

“Aww come on Marcy, take it seriously,” Jake whined. “You don’t have to dare me for that.”

“Fine. Bonnie.” The princess looked up guiltily from her notes at the sound of her name. “Truth or dare.”

“Um, truth.”

“What are you writing in that notebook of yours?”

The rest of them ‘ooo-ed’. 

“I already told you,” she said while closing it and sliding it into her bag. “It’s science.”

“I don’t believe you.”

“Yeah Bonnibel whatchu writing? A love letter or something?” Jake teased.

The princess blanched as much as someone made of gum could.

“I’ll believe you if you show me,” Marceline challenged.

“Sorry Marcy but I didn’t choose dare. Believe me or don’t: it’s your choice.” 

“Boring, but fine.”

They continued for another few rounds before they decided to call it a night. True to his word, Jake took everyone to their homes carrying them all in the form of a massive, four-legged bus.

\-----

A raid of the candy monarch’s garden on Thursday only proved to further spur her curiosity. The roses were in bloom, full and a deliciously deep red. Marceline finished drinking the colour from one bush, leaving them a pure  
white and was halfway through another when she heard a familiar voice and a string of curses. 

“How does she make it seem so easy? She just…” Marceline couldn’t make out the rest of the sentence. “–Probably wouldn’t even like it anyways.” The thump of a hardcover closed and purposeful footsteps along the garden  
path. 

Her mind was blank except for the need to hide as she flew into the dense foliage of a neighboring cotton candy tree. 

The footsteps stopped when they reached the roses. Marceline poked her head out of the spun sugar leaves to look. 

The princess crouched in front of her flower beds, setting her book beside her on the path. A hand caressed the bloom of one of the white roses while a scientist’s eye inspected. They settled on one abandoned partway  
between red and white. 

The vampire held in a breath she didn’t particularity need.

One more brush of her thumb against the petals and Bonnibel stood with the notebook loosely in her hand.

“Hope you liked them.” The princess said to no one. “I wanted white roses anyways.” 

Marceline waited until the other woman was well and truly gone before she finished draining the red from the rest of the flowers. 

\-----

She saw it again when she flew to Simon’s for a jam sesh; laying open on the balcony railing as Bonnibel tapped her pen on her chin and foot on the floor. 

“Not a lot of good light left for science, Princess!” Marceline called.

Bonnibel nearly dropped the thing right off the tower.

\----

Sunday saw her wake to the chime of a phone she forgot to mute and a new text message.

**Bonnie:** _Wanna come over for a bit?_

Marceline woke up rather quickly at that, taking an extra-long shower before saying yes. She gave herself a quick once over and mentally checked off her routine as she got ready. 

Teeth brushed? Yep. 

Pants? She looked down. Check. 

Deodorant? Check? Yep.

She mulled over the invitation as she flew. Was it a hang out kinda hanging out with movies and stuff or did she need a guinea pig for a new experiment. Was it serious? Did something happen? Or was Bonnie just bored? 

Another message told Marceline to meet her in the lab. Guinea pig night it is then.

She knocked on the window a few times and waited. There was the scrape of a heavy object being dragged and crash before Bonnibel’s crown appeared and another minute and a thump before her face did. The window was  
opened and the vampire gave the lab a quick once over. 

It was dimmer than usual and Bonnibel had set up a projector screen and a couple of bean bag chairs. And that book sat on a table. 

“What’s up Peebs?”

“I managed to synthesize dreams into movies! Well, there’s a few middle steps: like first you have to convert the brainwaves into images and knit them together so –“she noticed Marceline’s glazed over expression. “Uh, I  
thought we could watch a few.”

“Seems cool dude. Whose have you got?” 

“Well, I got of few of Jake’s here, Root Beer Guy’s are kind of cool and one of Peps’ but it is weird. Like, it’ll make that tape we found in the woods seem vanilla bean baby tier.

They agreed on watching Root Beer Guy’s first. 

“They’re kind of like detective stories but they don’t usually ever end or he starts freaking out because he’s forgotten to put in his straw that morning or something,” the princess explained as she made the necessary  
connections and flipped the necessary switches. The lights turned off completely. 

Marceline never realized the candy people dreamed of much of anything at all.

The soda based candy citizen flickered to monochrome life on the screen.

“He dreams in black and white?”

“Yeah, I don’t really know why.”

They settled themselves on the chair and watched as a surprisingly elaborate plot of gangs, crooked cops and lost love unfolded. 

Root Beer Guy sat on the doorstep of his former wife, head in his hands before he tossed symbol of the responsibilities that had caused him so much pain away and into a hedge.

“Dang, who knew the little guy had dreams like this in him?” Marceline turned to Bonnibel. “Did you record your own too?”

“…Yeah.” The princess plucked at the hem of her shirt. “Yeah, I did. Last week.” 

“Anything interesting or do you dream in math?” Marceline teased.

The princess sucked in a breath like she’d been punched and turned to face her fully, face almost the same vivid shade as her hair. Lips just began to form the words ‘well actually’.

“Princess, Princess, Princess!” A trio of banana guards yelled as they jostled against each other at the doorway. They could fit into the room one at a time but they hadn’t the forethought. Instead they bumped their cylindrical  
bodies and shouted over each other.

“It’s an emergency!” cried the one in the middle, reaching his stubby arm forward to try and lever himself out of the banana bunch. 

“A crime-inal one!” the guard on the left added.

“Princess, its Starchy!” the right one shouted. “He’s been digging graves!”

Bonnibel pinched the bridge of her nose and flicked the lights back on. “Well, duh, that’s his _job_! You know, Starchy the _grave digger_.”

“Yeah, but he’s digging them back up again! He said ‘now it’s Starchy’s time to shine’” the banana recounted in a surprisingly good impression of the old grave digger. “a-and he started hovering in the air –”

“It was really scary,” the leftmost guard finished. 

The princess sighed, “Sorry… I think I need to deal with this.” 

“Need any help?”

“Nah, this has been happening ever since he found that cursed amulet. More of a nuance than anything really. I’m going to have to confiscate it if he keeps this up.” She went into to the supply closet and returned with a spray bottle. “I just spray him and let Peps do some of his chanting. Calms him right down.” She fiddled with the nozzle, then lined up a shot at the wall with one eye closed, the tip of her tongue poking out in concentration. 

Marceline expected something a little more impressive as she watched the water drip down the wall in long streaks but Bonnibel seemed satisfied. 

“Alright boys.” She hung it on her belt loop by the trigger. “Let’s do this.” 

And with that, the princess was gone, followed by her yellow entourage and Marceline was alone. 

A week of curiosity drew her to the book left unattended on the table, a pen carelessly left within and ever so tantalisingly marking the most recent place. 

A quick look wouldn’t hurt. She’d probably just see a bunch of boring notions and equations. Absolutely harmless.

She picked it up and began to read. Bonnibel’s precise, elegant hand filled the page. \

_Promise me you’ll never settle_  
_Promise me you’ll find shimmer in every mad hue_  
_The sky does not need to be blue_  
_That’s what I learned from you_

_Promise me you’ll save your magic_  
_For someone who wants sparkle in their life_  
_Let’s build a stone house in the woods_  
_I don’t know how to not be good to you_

_You won’t need a scale_  
_To weigh how much love I have for you_  
_You won’t need a clock_  
_To count the minutes I will wait for you_  
_You won’t need a level_  
_I’ll walk on crooked floors if need be_  
_I don’t want to forget how to say_  
_I love you_

Her heart stuttered to life in her chest. She knew she probably should stop reading but couldn’t bring herself to stop. An index finger tracing the blue ink, she continued.

_Promise me if we go ten years_  
_Without speaking you will still dream of me_  
_You’ll grow your hair out I’ll cut mine_  
_I’ll think about you all the time_

_Promise me when our bones get brittle_  
_You will still find glitter in everyday life_  
_Come blue rain or pink sunshine_  
_We’ll still make love all the time_

She blushed and felt the beginnings of an involuntary smile. The phrase was equal parts proper and sweet and so very Bonnie. Memories of younger times centuries past sprang to mind. 

_Kiss me on my collarbones_  
_And I will surely rise_  
_To watch with you the new day_  
_To sit there warming your side_

_Did you know birds can learn new songs_  
Did you know night was so short  
Did you hear the last thing I whispered 

The next line few lines were struck through, and then scribbled out rendering them completely illegible.

_I hope not, I hope not_

_Rest your hands on my cold knees_  
_So I may drift to sleep_  
_To dream of curling round you_  
_And wake to find you with me_

_I don’t want to forget how to say  
I love you_

A strange feeling in her stomach and a hearth fire in her heart, she closed the book. 

She wasn’t meant to see that. Not yet. 

But she was willing to wait, as long as it took.

**Author's Note:**

> Idk when in the series this one would be set but probably ambiguously pre-Stakes?  
> Written for day 2 of Bubbline week - prompt 'role reversal' and for my best buddy who requested the plot. Here's hoping he (and you) enjoy it c:  
> The song lyrics were lovingly borrowed from Promise Me by Big Tree - go give it a listen if you feel so inclined.


End file.
